I've tested with 2 players only at one NL table, and it seems that when one player posts BB (20) and second folds after posting SB (10), the total is 30 but the pot won by first player is 20.

I've tested also by betting / folding after flop and pot is also different than total chips.When there is only one pot, the amount given back to winning player is the total and not only the difference (total-chips put by himself).

By following more accurately the action at the table I see that in the end the chip count is OK for both players, but the 2 passes credit (players gets back his chips, then gets the pot) could be misleading.